Fix !important parsing for yet more CSS properties.

These are discovered by running through the entire test suite in a mode
where every successful value parse is re-tried with “ !important” added
at the end, and then picking out the relevant failures. (There are some
cases with e.g. unbalanced parentheses which are false positives.)

Fixed: 348442541
Change-Id: Ib2444d64575a32fa21a427a3c3112fa5519de3c4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5651125
Reviewed-by: Anders Hartvoll Ruud <andruud@chromium.org>
Commit-Queue: Steinar H Gunderson <sesse@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1319651}